Effects of pre-ovulatory follicle growth on luteal function and fertility response to modulation of peri-ovulatory endocrine milieu in cattle

• Grant number: 12/04004-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: June 01, 2012
• End date: May 31, 2015
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Mario Binelli
• Grantee: Guilherme Pugliesi
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 11/03226-4 - Signatures of receptivity, AP.TEM

Abstract

The understanding of endocrine, cellular and molecular mechanisms that can result in greater pregnancy rates is crucial for the fertility improvement needed in cattle. Recent evidences indicate that the progesterone (P4) secretion from corpus luteum (CL) during early diestrus is affected by ovulatory follicle size and has a significant effect on embryo development and pregnancy rates. However, the effects of manipulation of follicle growth on luteal function and the fertility response to modulation of peri-ovulatory endocrine milieu are not known. Thus, the current project aims to study the effects of pre-ovulatory follicle growth on the hormonal, cellular and molecular mechanisms involved in the luteal function and to evaluate the fertility response to modulation of peri-ovulatory endocrine milieu in beef cows inseminated after estrus synchronization. In Experiment 1, follicle growth will be modulated to evaluate the cell composition, gene expression and ultrasound characteristics in the CLs from small and large pre-ovulatory follicles. In Experiment 2, the peri-ovulatory endocrine milieu will be modulated through follicle growth and supplementation with exogenous P4 to result in greater or lesser P4 concentrations post-ovulation. This will allow the study of the effects of different endocrine milieus on fertility of beef cows. The current purpose will permit the establishment of an experimental model that gradually increases the P4 concentrations during the beginning of diestrus, and indicate the effects of follicle growth on the luteal function. In addition, it is expected that this project will identify hormonal treatments that modify the peri-ovulatory endocrine milieu, and consequently, improve the fertility in beef cattle.

Scientific publications

(4)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

PUGLIESI, G.; SANTOS, F. B.; LOPES, E.; NOGUEIRA, E.; MAIO, J. R. G.; BINELLI, M.. Improved fertility in suckled beef cows ovulating large follicles or supplemented with long-acting progesterone after timed-AI. Theriogenology, v. 85, n. 7, p. 1239-1248, APR 15 2016. (11/03226-4, 12/04004-8)

PUGLIESI, G.; SCOLARI, S. C.; MESQUITA, F. S.; MATURANA FILHO, M.; ARAUJO, E. R.; CARDOSO, D.; SALES, J. N.; MARTIN, I.; SA FILHO, M.; BERTAN, C. M.; et al. Impact of Probing the Reproductive Tract During Early Pregnancy on Fertility of Beef Cows. REPRODUCTION IN DOMESTIC ANIMALS, v. 49, n. 4, p. E35-E39, AUG 2014. (11/03226-4, 12/04004-8)

PUGLIESI, G.; OLIVERIA, M. L.; SCOLARI, S. C.; LOPES, E.; PINAFFI, F. V.; MIAGAWA, B. T.; PAIVA, Y. N.; MAIO, J. R. G.; NOGUEIRA, G. P.; BINELLI, M.. Corpus Luteum Development and Function after Supplementation of Long-Acting Progesterone During the Early Luteal Phase in Beef Cattle. REPRODUCTION IN DOMESTIC ANIMALS, v. 49, n. 1, p. 85-91, FEB 2014. (11/03226-4, 12/04004-8)

SCOLARI, SAARA CAROLLINA; PUGLIESI, GUILHERME; STREFEZZI, RICARDO DE FRANCISCO; DA SILVA ANDRADE, SNIA CRISTINA; COUTINHO, LUIZ LEHMANN; BINELLI, MARIO. Dynamic remodeling of endometrial extracellular matrix regulates embryo receptivity in cattle. Reproduction, v. 153, n. 1, p. 49-61, JAN 2017. (11/03226-4, 12/04004-8)